Heat pump water heater



y July 18, 1950 A. w. RUFF HEAT PUMP WATER mm 2 sheets-sheet 1 Filed May 17, 19,49

A. W. RUFF HEAT PUMP WATER HEATER AJuly 1s, 195o- 2 Sheets-Sheet 2 Filed May 17, 1949 .afar irvlvlllllInlllllllrf/f ,laIIIIIIIIOfrlaflllllllfllfl llllflllrlla ril/llllnrllfdlll allg.; y W

Patented July 1s, 195o UNITED STATES PATENT OFFICE Alonzo W. Rui, York, Pa., assignor to V. C. Patterson & Associates, Inc., York, Pa., a corporation of Pennsylvania Application May 17,1949, Serial No. 93,812 11 claims. (ci. 62-129) My invention relates to heat pumps and more particularly to a water heater which operates hot water; and, at the same time, serving to cool p and dehumidify the air of the room or space in which the water heater is operated.

My invention is best understood by the following description taken in connection with the accompanying drawings, in which Figure 1 shows, in vertical section, a preferred structural embodiment of my invention,-

Figure 2 is a view taken on a line which is at 90 to line 2-2 vof Figure 1,

Figure 3 is aview taken on a line which is at 90 to line 3--3 of Figure 1,

Figure 4 is a view taken on a line which is at 90 to line t-Il of Figure 1,

Figure 5 shows, somewhat diagrammatically, a modification of the structure shown in Figure 1.

Referring now to Figures 14, the water storage tankpIil is surrounded on the sides and bottom by insulation I I and an outer shell or cover I2. The water storage space Within the tank is defined by members IIJ, i3 and It. The latter functions as the principal heat exchanger and will be hereinafter more fully described. Member I3 comprises an inverted dome-shaped pocket in the top of the tank, as can best be seen from Figures l and 5. The motor-compressor unit l5 is mounted within this pocket. for example on the brackets, secured to the side walls, as-shown. The evaporator unit I6 is mounted at the top of the tank, and is preferably provided with a drip pan Il. A block of insulation IB in the form of an annular ring is secured intermediate the drip pan and the top of the tank. As best seen in Figure 2, the evaporator unit is in the shape of an annular ring with about 60 of the circle cut out. Immediately below the said cut-out is a service opening I9 (see Fig. 3) for the motor compressor unit. In the center of the evaporator, mounted on a frusto-conical plate assembly 20, is a motor '2I having fan blades 22 and 23 on opposite ends of its shaft. A hollow linsulation block 24, also frusto-conical in shape, completes the chain of insulation which surrounds the water storage tank. The evaporator unit is 2 surrounded by a louvered side panel 25 around its outer periphery, and a fan cowling 26 extends around the top inner periphery so that the surrounding air, as shown by arrows in Fig. 1, is circulated through the evaporator coils by fan blades 22. Fan blades 23 Withinl the insulated space, circulate air, heated by the losses of the fan and compressor, in heatexchange relation tothe water inthe upper part of the tank.

The heat exchanger I4 of Fig. .1, consists of a double-walled hollow cylindrical member secured to member I3 and extending downwardly therefrom to the bottom of the tank I0. It is secured in watertight relation both to I3 and I0. Refrigerant, circulated by the motor-compressor unit, is passed between the double walls and there gives up its heat to the water in the tank; Fin members 2l (Figures 1 and 4) are attached to the midsection of the heat exchanger to provide an increased area of heat transfer surface.

The path of the refrigerant starting at the high pressure side of the compressor is through line 28 `to the top of the heat exchanger I0, out the bottom of the heat exchanger through line 29 to a liquid strainer 30, thence to a thermal expansion valve 3i, the said strainer and valve being conveniently located in the cut-out space at the level of the evaporator I6; The refrigerant then passes through the coils of the evaporator unit i9 and back to the low pressure side of the compressor through suction line 32.

The electric power lines 33 may be led down through the insulation surrounding the tank, as shown in Fig. 4 to a suitable plug-in receptacle mounted at the bottom of the tank. A thermostat 3l is placed in the power line in heat exchange relation to the tank Wall to control the transfer of heat to the water in the tank.

As hereinbefore stated, the heat cycle of the apparatus of this invention is substantially identical with that shown and described in my copending application Serial Number 91,595, so it need be only briefly described here.

The refrigerant system is charged to a point where the heat exchanger it is filled with liquid from the bottom to a point about even with the lower end of ythe lin structure 2l. The refrigerant charge should be such as to maintain this liquid level during operating conditions to take advantage of the liquid subcooling principle disclosed in my copending application mentioned above. Under operating conditions, refrigerant under pressure is allowed to expand in the evaporator coils Where it picks up heat from'the surrounding atmosphere. Refrigerant gas is then pumped out of the evaporator at low pressure, compressed to a superheated gaseous condition bythe motor compressor unit and led to the top of the heat exchanger where it comes into heat exchange relation with the water in the upper part of the tank. That part of heat exchanger Il which lies above the fin structure 21 then serves as a desuperheater for the refrigerant, after which condensation takes place in that part of the heat exchanger which is surrounded by the iin structure 21. The condensed refrigerant is then subcooled in the bottom of the heat exchanger and the cycle is repeated.

It should be noted that marked stratification of the Water in the tank takes place so that the desuperheating, condensing and subcooling functions of the heat exchanger occur at substantially the same temperatures in each cycle. 'I'he hottest water accumulates in the top of the tank and is subjected to the heatof the superheated refrigerant. Also the heated air from the motorcompressor and fan units acts by convection and conduction to transfer' heat to the water in the, upper reaches of the tank. The greatest heat transfer takes place in the water surrounding the condenser section of the heat exchanger, and, during normal operation of the heater, there will be a second stratum of water in the tank at that point whichis at a somewhat lower temperature than that in the uppermost portionl A third strata of water surrounds the subcooling section of the heat exchanger and will be only a few Y the apparatus is effective to reduce dampness.

I claim:

1. A water heater of the heat pump type, in which a refrigerant is used as the working fluid, comprising in combination: a hot water storage tank; a refrigerant evaporator unit mounted on said tank and adapted to absorbheat from the degrees warmer than the sourceof supplyV or f make-up water.

Figure 5 shows a modification of the structure of Figure 1 which will qualify this apparatus for use in certain localities of the United States, which require two thicknesses of metal between refrigerant and water to be used in homes or public buildings. Since the only changes necessary are those to the heat exchanger, only so much of the apparatus is shown in this drawing as will make those changes apparent.

The double-walled heat exchanger I 4 of Figure 1 is replaced by a .single-walled member 50. Heat exchangecoils 5|, 52 'and 53 are fitted to the inner wall of this member, in heat exchange relation thereto. These coils are series-connected and function in exactly the same way as does member uA of Figure 1. A uqam-receiver svisplaced between coils 52 and 53 in order to insure that refrigerant passing' to the subcooling coil 53 is in liquid form. All other refrigerant connections are the same as described with reference to Figure 1 and this apparatus will perform substantially aswell.

From the above, it will be apparent that I have shown and described a hot water heater which is compact in design and capable of easy installation, since`only the water pipe connections need be made. The power requirements are small so that the power line can bemerely plugged in to the nearest convenience outlet. In operation, this unit is found, bytest, to have a c oemcient of performance of better than 4.5. Economy of operation therefor combinesA with the other salient advantages such as no flame (and hence no flue connections), which renders the apparatus capable of installation in almost any desired location, to produce a new and novel type of water heater which willhave Widespread adaptation and use. Among the/many other advantages afforded by this apparatus, that of cooling and dehumidfying the air in the room or space in which the apparatus is located, is worthy of .air at the .prevailing room temperature; heat transfer means of the type in which refrigerant is circulated, said means being mounted in heat conducting relation with a wall of said tank and extending substantially from top to bottom thereof; a motor compressor unit mounted in heat exchange relation to the water in said tank; closed vfluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit for the refrigerant connecting the bottom of said heat transfer means to said evaporator; and means responsive to the temperature of the water in said tank to control the transfer of heat thereto.

2. A water heater of the heat pump type, in which a refrigerant is used as the working fluid, comprising in combination: a hot water storage tank; a refrigerant evaporator unit mounted on said tank and adapted to absorb heat from the air at' the prevailing room temperature; an enclosed flue-like member centrally and vertically disposed in said tank; heat transfer means, of the type in which refrigerant is circulated, disposed in heat conducting relationship with said member and extending substantially from' top to bottom thereof; a motor compressor unit mounted in heat exchange relation to the water in said tank; closed fluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump f gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at yhigh pressure to the top of said heat exchanger; a closed conduit for the refrigerant connecting the bottom of said heat transfer means and said evaporator; and meansresponsive to the temperature of the water in said tank to control the transfer of heat thereto.

3. A water heater of the heat pump type, in which a refrigerant is used as the working uid, comprising in combination: a hot water storage tank; a flue like member centrally and vertically disposed in said tank and extending substantially from' top to bottom thereof; a second flue like member concentrically disposed within said rst named member and coextensive in length therewith; means closing the space between said members at each end thereof, said means and said members thus deflning a heat exchanger through which refrigerant may be circulated in heatconducting relation to the water in said tank; a refrigerant evaporator unit mounted on said tank and adapted to absorb heat from the air at the to the water in said tank; closed fluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit for said refrigerant connectingthe bottom of said heat exchanger opposite ends, said heat `exchanger being centrally and vertically disposed in said tank and extending substantially from top to bottom thereof; a refrigerant evaporator mounted on said tank and adapted to absorb heat from the air at the prevailing room temperature; a motor compressor unit mounted in heat exchange relation to the water in said tank; closed fluid conduits, extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low presn sure from said evaporator and deliver saidv refrigerant at high pressure to the top of said heat exchanger; a closed conduit for Saidrefrigerant connecting the bottom of said vheat exchanger and said evaporator; and means responsive to the temperature of the water in said tank to control the transfer of heat thereto.

5. A water heater of the heat pump type, in which a refrigerant is used as the working fluid, comprising in combination: a hot Water storage tank having a depression in thetop thereof; a refrigerant evaporatorunit mounted on said tank and adapted to absorb heat from the air at the prevailing room temperature; a heat exchanger of the type in which refrigerant is circulated comprising a pair of spaced concentric cylindrical members closed at their opposite ends, said heat exchanger being centrally and vertically disposed in said tank and extending from the bottom of said depression to the bottom of said tank, a motor compressor unit mounted within said depression in heat exchange relation to the water in said tank; closed fluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator` and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit for said refrigerantconnecting the bottom of said heat exchanger and said evaporator; and means responsive to the temperature of the water in said tank to control the transfer of heat thereto.

6. A Water heater of the heat pump type, in which a refrigerant isvused as the working fluid, comprising in combination: a hot water storage tank having a dome-shaped depression in the top thereof; a refrigerant evaporator mounted on said tank and adapted to absorb heat from the air at the prevailing room temperature; a heat exchanger of the type in which refrigerant is circulated comprising a pair of spaced concentric cylindrical members closed at their opposite ends, said heat exchanger being centrally and vertically disposed within said tank and extending from the bottom wall of said .depression to the bottom of said tank; a motor compressor unit mounted within said depression in heat exchange relation to the water in said tank; closed uid conduits extending` between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure tothe'top of said heat. exchanger; a closed conduit for said refrigerant connecting the bottom of said heat exchanger and said evaporator; an inverted, cup shaped member, thermally insulated and mounted on said tank above said motor compressor unit; an electric motor -mounted within said member in heat exchange relation to the water in said tank, said motor having a first fan within said cup shaped member adapted to circulate air heated by the losses of said motor and said motor compressor unit in heat exchange relation to the water in said tank, and a second fan above said cup shaped member, operated by said motor, and adapted to circulate air at the prevailing room temperature through said evaporator unit; and means responsive to the temperature of the water in said tank to control the transfer of heat at the prevailing room temperature; a motor compressor unit mounted in heat exchange relation to the water in said tank; closed fluid conduits extending between said compressor and the i pressure from said evaporator and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit for refrigerant,con necting the bottom of said heat exchanger to said evaporator; and means responsive to the temperature of the Water in said tank to control the transfer of heat thereto.

8. A water heater of the heat pump type, in which a refrigerant is used as the Working fluid, comprising in combination: a hot water storage tank; a flue like member centrally and vertically disposed in said tank; a heat exchanger of the type in which refrigerant may be circulated comprising, a first coil located in the upper sectionof said flue, a second coil located in the midsection of said flue, a third coil located in the bottom section of said flue, the said coils being connected in series and each disposed in heat conducting relation with the wall of said flue; a liquid receiverv serving as a liquid seal and connected between said second and third coils; a refrigerant evaporator mounted on said tank and adapted to absorb heat from the air at the prevailing room temperature; a motor compressor unit mounted in heat exchange relation to the water in said tank; closed fluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit `for refrigerant connecting said third coil to said evaporator; and means responto control the transfer of heat thereto.

9. A water heater of the heat pump type, in which a refrigerant is used as the working fluid,

comprising in combination: a hot water storagetank having a dome-shaped depression in the top thereof; a ilue like member centrally and vertically disposed within said tank and connected at its upper end to the bottom wall of said depression, the said member extending therefrom to the bottom of said tank; a heat exchanger of the type in which refrigerant may be circulated, said heat exchanger being disposed in said ilue in heat conducting relation with the wall thereof and extending substan- .tially from top to bottom thereof; a refrigerant evaporator mounted on said tank and adapted to absorb heat from the air at the prevailing room temperature; a motor compressor unit mounted within said depression in heat exchange relation to the water in said tank; closed fluid conduits extending between said compressor and the evaporator and heat exchanger to enable the corn-v pressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure to the top of said heat exchanger; a closed conduit for refrigerant connecting the bottom of said heat exchanger to said evaporator; and means responsive to the temperature of the water in said tank to control the transfer of heat thereto.

10. A Water heater of the heat pump type, in which a refrigerant is used as the working iluid, comprising in combination: a hot water storage tank having a dome-shaped depression in the top thereof; a -fiue like member centrally and vertically disposed within said tank and connected at its upper end to thebottom wall of said depression, the said member extending to the bottom of said tank; a heat exchanger of the type in which refrigerant may be circulated comprising, a first coil located in the upper section of said flue, a second coil located in the midsection of said flue, a third coil located in the bottom section of said iiue, the said coils being connected in series and each being disposed in heat conducting relation with'the wall of said ue; a liquid receiver serving as a liquid seal and connected between said second and .third coils; a refrigerant evaporator mounted on said tank and adapted to absorb heat from the air' at the prevailing room temperature; a motor compressor unit mounted Within said depression in heat exchange relation to the water insaid tank; closed iluid conduits extending between said compressor and the evaporator and heat exchanger to enable the compressor to pump gaseous refrigerant at low pressure from said evaporator and deliver said refrigerant at high pressure to the top oi said heat exchanger; a closed conduit for refrigerant connecting said third coil to said'evaporator; and means responsive to the temperature of the water in said tank to control the transfer of heat thereto.

1l. A water heater as defined in claim 10 and including: an inverted cup-shaped thermal insulating member mounted on said tank above said motor compressor; f an electric motor mounted within said member in heat exchange relation to the water in said tank; a first fan blade mounted within said member driven by said motor, and adapted to circulate air heated by the losses of said motor and said motor compressor unit in heat exchange relation to the water in said tank; andy a second fan blade mounted outside said member driven by said motor, and adapted to circulate air at the prevailingtroom temperature through said evaporator uni ALONZO W. RUFF.

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,937,288 McGraw Nov. 28, 1933 2,066,161 Roessler Dec. 29, 1936 2,095,017 Wilkesl Oct. 5, 1937 2,162,245 Comstock June 13, 1939 

